Abaixo está uma instrução que descreve uma tarefa de geração de SQL, combinada com uma entrada que fornece mais contexto sobre os esquemas de tabela disponíveis. Escreva o código SQL que responda adequadamente à solicitação
 ###Instrução: Qual é o PSIP Digital para canais acima de 15 com o callsign CFTU-DT?
 ###Tabelas: CREATE TABLE coaching_history (coaching_history_id AUTO_INCREMENT PRIMARY KEY, Coach VARCHAR, Years VARCHAR, Record VARCHAR, Conference Record VARCHAR, Overall Win Percentage VARCHAR) CREATE TABLE made_the_cut (made_the_cut_id AUTO_INCREMENT PRIMARY KEY, Player VARCHAR, Country VARCHAR, Year(s) won VARCHAR, Total INT, To par VARCHAR, Finish VARCHAR) CREATE TABLE past_winners_and_runners-up (past_winners_and_runners-up_id AUTO_INCREMENT PRIMARY KEY, Year VARCHAR, Date Final VARCHAR, Venue VARCHAR, Prize Money VARCHAR, Champion VARCHAR, Runner-up VARCHAR, Score in final VARCHAR, Commercial name VARCHAR) CREATE TABLE ships_attacked (ships_attacked_id AUTO_INCREMENT PRIMARY KEY, Date VARCHAR, U-boat VARCHAR, Name VARCHAR, Nationality VARCHAR, Tonnage (GRT) INT, Fate VARCHAR) CREATE TABLE television_stations (television_stations_id AUTO_INCREMENT PRIMARY KEY, Call sign VARCHAR, Broadcast channel INT, Digital PSIP INT, Cable channel INT, Network VARCHAR)  
SELECT Digital PSIP FROM television_stations WHERE Broadcast channel > 15 AND Call sign = cftu-dt